Safety lock



W. HAAG SAFETY LOCK Fi'led Sept. 22.' 1934 mE-EW Patented Jan. ll2, 1937UNITED STATES SAFETY Loox wilhelm mag, Pforzheim, Germany Applicationseptember 22,1934, serial No. 745,114 In Germany November 21, 1933 1Claim. (Cl. 'l0-75) My invention relates to improvements in key operatedlocks of the type, the locking bolt of which is slidably mounted in acasing or support and is cooperatively associated with pivoted levertumblers to be engaged and swung around their Ipivot by a rotary key. y

With the, object of enabling manufacturers to make by mass productiongreat numbers of locks of this type and of standard sizes whichindividually differ from each other in the shape of their key, and thusmaking those locks as'safe as possible against being picked,4 usually aplurality of t blers of different design, viz. differing from ach otherin the shape of their contour lines, orking faces, edges, in theposition of the notches, gatlngs, indentations, projections etc.provided thereon for engagement with the key and the bolt, are employedin one and the same lock in such manner, that the said tumblers are 2oassembled on their pivot pins in different permutations and sequenceclosely on top of each other or dierently spaced from each other.

However as a matter of fact known to experts in this ileld many locks ofthis design can be g5 picked by thieves almost with certainty, since thecharacteristics ofthe swinging motion of the individual tumblers can befeelingly ascertained by reason of the very diiference in shape of thetumblers at the place, where they face the key- 30 hole. I

The primary object of this invention is to provide an improved lock ofthe type concerned and of greatly simplied design, which is saferagainst being picked by thieves than its prede- 35 cessors known in thetrade, and which can be produced by mass production at low cost.

More 'especially the invention aims at so designing the improved lock,that only tumblers of one single design are employed, viz. which are '40of identical shape in one and the same lock and in all the great manylocks, made by mass production so as todlifer from each other in theform of their keys.

The nature and scope of this invention are .45 briey outlined in theappended claim and will be more fully understood from the followingspecication taken together with the drawing, in

which a lock having 14 tumblers is shown by way '50 of example:

the lock at right angles to its longitudinal axis of symmetry;

Figs. 4 and 5 are plans intended to elucidate jointly with Fig. 2 thegist of this invention, which consists therein, that the tumblers byreason of 5 the symmetric form of their contour line facing the key areinvertible and reversible on their longitudinal and their transverseaxis, so as to be capable of being assembled on their pivotsindependently of each other in four different posil0 tions and by way ofcombination and permutation in a vast number of different ways; Fig. 6is a. plan showing by way of an example a. key, of which the outerworking edges of the teeth are in alignment with each other. 15

The main plates of the lock are the plates a and b which are connectedwith each other by the pins c, d, e and f. .Between these main platesthere is the bolt g with the pins h, i, lc, l, m anda, the cylinder oand the tumblers p,'which are 20 adapted to be swivelled on the axes qand r; The tumblers are held by springs s in such a position, thataccording to their positions, their notches either embrace the pins ofthe bolt, thus impeding the movement of the bolt g, or do not embracesaid pins, thus oiering no impediment to the movements of the bolt. Byturning the key, the tumblers are separatedfrom the pins 11,1', k and lthereby releasing the bolt and rendering it possible to move it by meansof the cam cylinder o.

The lock proper is enclosed in the case u. The tumblers employed areformed with two key sweep edges and are all of identical shape, namelysymmetrical as to the disposition of said vkey sweep edges relatively toan axis of symmetry running through their fulcrum point, so as to becapable of being reversed face for face. These axes are firmly-connectedwith the lcck plate a and enclosed within the lock plate b. Figs. 4 and5 show the different positions of the 40 tumblers p. The positionsdesignated by I and 3 are locking positions of the tumblers, whereas thepositions 2 and 4 represent merely securing positions of the tumblers.The dotted lines indicate the tumblers swung, out. To move the4 45 bolt,only the tumblers in the positions I and 3 must be swung, whereas thetumblers inthe positions 2 and 4 must remain unmoved. For this purposethe key is provided with grooves t at those points where no tumbler isto be actuated.

The key, therefore, is given the task to swing the locking tumblersembracing the pins of the bolt, i. e. in the positions l and 3 and toavoid establishing contact with the tumblers in the positions 2 and l.55

justed tumbler-arms.

It will be seen from Figs. 4 and 5 that a 'tumbler p can occupy 'any of4 positions each` dii'- ferent from the others. By means of a spring, s,the tumbler is held in the position it is occupying at the time orforced back into it. 'Ihe tumblers have the function either to arrestthe bolt or to secure it, in a position ready for action, according towhich of the four diierent positions they are occupying at the time.

The configuration of the tumblers employed may differ. It is, however,essential, that in any one lock only tumblers are used which areidentical in shape, so that the latter may be mutually adjusted andchanged from one position to another. The uniformity of the tumblerswith regard to size and configuration necessarily includes as a furtheressential characteristic feature of the present invention that, not onlyall the locking tumblers and also al1 the securing tumblers are swungout to the same extent, but that for both kinds ,of tumblers the angleof oscillation is of the same magnitude, and furthermore, that with eachpossible position the tumblers always offer themselves uniformlyadjusted towards the keyside, so that the key is always made to face anumber of uniformly shaped anduniformly ad- These properties whichfollow as a natural consequence of the uniformity of the tumblers,render it practically impossiblel that the lock be successfully picked.

Various changes and modifications may be conveniently made in thestructural details of locks of the improved design, described above,without substantially departing from the spirit and the salient ideas ofthis invention.

By abandoningthe transposition of the tumshapes, i. e. tumblers ofdifferent shape, in c'onnection with one and the same lock would bepossible, provided, however, that at least all tumblers arms turnedtowards the key side are of identical shape and that all tumblers aremade to describe an angle of oscillation of the same magnitude. Thiswill not, however, enhance the degree of safety or reliability of thelock. The `ernployment of more than one form or shape of the tumblerwould be equivalent to the discarding of the simple constructionallprinciple in favour of one less simple.

With regard to the key, the uniformity of the tumblers render it furtheressential, that the separate wards, actuating the locking tumblers, must.be of equal length. At the points where the key must not actuate thetumblers which are in unlocking position, the key should be providedwith grooves between'the separate parts of the wards and these groovesmust be of such depth, that the unlocking positioned tumblers are nottouched by the key. Corresponding to the opposed positions of thetumblers the key is provided with two series of wards, f. e. a series oneither edge. v

I claim:

In a key operated lock having a support and a bolt formed with lockingpins and slidably mounted on said support, the combination of aplurality to said axis of symmetry.

WILHELM HAAG.

blers theemployment of a plurality of tumbler of tumblers for lockingsaid bolt, each of said 30

